In the oil and gas industry, pipeline projects are invested in and developed in order to add more capacity to the energy transmission system, increase outflow volumes, and to replace aging infrastructure. Construction is typically undertaken during the spring and summer and projects are brought on-line and put into service in the fall and winter. Pipelines are developed in order to meet supply and demand needs for transportation of natural gas, liquefied natural gas (LNG), crude oil, heating oil, fuel oil, propane, and other petroleum products as well as drinking water and water main infrastructure. New projects add miles of pipeline capacity for the millions to billions cubic feet per day of natural gas production, thousands to million barrels of oil production, and are constructed according to economic feasibility, permitting, state and federal regulation, and environmental impact. Replacement of pipelines is undertaken to fix integrity problems found during hydrostatic pressure testing, and to address known defects such as corrosion, cracks, insufficient padding, leakage, emissions, as well as to upgrade outdated infrastructure.
During the construction and laying of underground pipelines, a trench or ditch is excavated, the pipeline is assembled and then lowered into the ground. The pipeline is covered up with dirt, soil or backfill padding material during the process of burying the pipeline. Heavy equipment such as an excavator, backhoe loader, or bulldozer, may be used to carefully bury the pipeline. However, extreme caution must be exercised in order to not damage or break the pipeline by causing impact with large stones or other debris. Additionally, it is important to lay and cover the pipeline with sufficient padding material and eliminate contact with rocks. An extremely efficient method of burying a pipeline is to utilize a specialized piece of equipment called a pipeline padding machine to pad or bury the pipeline with carefully processed soil and backfill material that does not contain large rocks, particles, or other debris. Pipeline padding machines or padding equipment operate by scooping, ingesting, self-loading, feeding or elevating backfill soil near the pipeline trench, separating, vibrating, screening, crushing, or removing rocks and debris, and then conveying, expelling and depositing the backfill padding material back down over, under and around the pipeline without damaging the critical pipeline integrity, pipeline welds, valves, components, and important anti-corrosive coatings.
The elevator or self-loading conveyor part of the padding machine that initially picks up the backfill material works by engaging horizontally arranged elevator flights or cleats attached to an endless conveyor chain driven mechanism. The flights scoop up soil and upwardly elevate the backfill material into the machine for screening and separating out rocks and other debris. However, when operating in wet soil conditions, or excessive mud or clay, material will build up on the padding machine elevator drive chain and drive mechanism causing clogging, strain, slowdown and eventual failure. To prevent build up, the machine operator is forced to frequently shut down the machinery for cleaning and maintenance. Frequent work stops and downtime are costly to the machine operator in terms of lost productivity and missed pipeline project development deadlines, therefore a solution to prevent clay and mud build up is needed.